Nut cutting tools are common and well known. They are used for the purpose of removing a poorly installed nut which has become rusted, and so corroded as to make normal removal thereof by unthreading impossible. By cutting and or breaking such corroded nut from a threaded throat on drains and water supply pipes, the original pipes are preserved against damage and/or loosening relative to a fixture.
Basically all nut cutting tools entail means for embracing the nut to be removed including a fixed cutting blade, a movable cutting blade guided for movement toward the fixed blade and means for forcibly moving it toward the nut therebetween for cutting the nut free of the pipe upon which it had been threadedly connected. In most cases the means for forcibly moving the movable cutting blade is a screw shank mounted on the nut embracing means in axial alignment with the movement of the movable cutter guided therein. A right angled lever or wrench on the free end of a screw shank is a common and well known means for tightening the screw shank toward the movable cutting blade and nut to be cut. Such arrangement poses a problem when applied to a nut on a drain pipe or water line up under a sink, face bowl and the like where no lateral space is available for the extended screw shank. The space thereunder being limited requires some means at right angle to the drive line of movement of the movable cutter blade.
U.S. Pat. No. 496,396 granted May 2, 1893 to E. Chaquette shows one form of moving means wherein linkages are employed between the drive line of movement of the cutter blade and a handle angularly disposed relative to such drive line.
In a more recent U.S. Pat. No. 3,660,897 granted May 9, 1972 to A. L. Gilmore the drive means is a dog leg pivotally mounted in a slotted brace between the guideway for the movable cutter and a screw supporting shank disposed perpendicular to the line of drive of the movable cutter. In this arrangement the pivoted dog leg has an arm disposed in a slot provided therefor in the movable cutter body so as to reciprocate the latter along the guideway and for reversably retracting the movable cutter therealong. An opposite arm of the pivoted dog leg has pivotal connection with the upper end of a connecting rod, the lower end of which rod is swivably connected to the upper end of a screw threaded in the perpendicularly disposed screw supporting shank and having a ball and socket connection with the rod so that the dog leg can be withdrawn via the mechanical linkage with the movable cutter blade to achieve retractibility thereof from as well as movement toward a nut to be cut.
The foregoing arrangement is vulnerable to break-down under the extreme pressure of force required to cut and break a nut. For example,, shearing of the pivots can occur at the mounting of the pivoted dog leg lever as well as between the dog leg arm and connecting rod at the upper end of the screw shank drive means.
The present invention seeks to alleviate such break downs by providing a more direct force transmitting medium between the angularly disposed drive means and the movable cutting knife.
Accordingly it is an object of the present invention to provide an improved nut cutting tool in which a more direct pressure can be directed to the movable cutting knife from an angularly disposed pressure exerting means. It is another object to provide a cutting head for supporting the movable cutting knife for movement in a cutting plane at right angles to a pressure exerting means.
It is yet another object to provide the cutting head with a fixed blade on a yoke for supporting the fixed blade in the cutting plane as close as possible to a nut to be cut to minimize the stroke of cut regardless of the size of the nut to be cut.
It is still another object to provide a handle like sleeve for the angularly disposed pressure exerting means and to provide such sleeve with a guideway normal to the cutting plane for guiding a cam wedge for movement within the handle like sleeve for wedgingly driving the movable cutting knife toward the nut to be cut.